British Deciduous Woodland (Epping Forest) 1 Flashcards
What is Epping forest?
High ground between River Roding and River Lea in north-east London (70% DW/ ancient trees over 400 years old)
Describe sucsession in Epping Forest.
- Succession – ancient natural climatic habitats of oak, beech, ash and birch (deciduous broadleaf woodland such as in Gloucestershire)
Epping forest - describe nutrient cycles.
- Nutrient cycles – leaves/fruit/bark – primary consumers, secondary consumers, tertiary consumers etc. Nutrient losses through leaching/some foods not digested (lignin/bone)/activity/heat and obtained through cation exchange
Describe the flows of leaf fall, death and decomposition seasonally.
- Temperate climate of the UK results in warmth and moisture speeding up decomposition processes, however cold and dry periods slow this down
- Annual leaf fall in Autumn = sudden transfer of nutrients (this is the main input of nutrients to soil). These are utilised the most in spring/summer
- Spring – more litter decomposition (abiotic conditions are better for decomposition)
What are the wood types in Epping forest.
- Nap Wood (4 layers of vegetation – upper canopy (tall hardwood trees – oak, lower canopy – younger trees, shrub layer – holly, and the ground layer – mosses, bluebells, honeysuckle, bracken)
What is the main store in a woodland?
- Biomass is the largest nutrient store due to the size of trees (greatest when trees have leaves)
What are the main physical factors influencing an ecosystem.
- Acidity of soil
- Peat deposits (northern Epping Forest)
- Annual autumnal leaf fall increases the nutrient input to soil
- High biomass (e.g. oak trees) meaning cation exchange is high
- High percentage of earth worms – high levels of decomposition
- Temperate climate (warm, moist) which increases the rate of decomposition
- Natural burning from lightning – causes secondary succession
- Drainage
- Relief
- Microclimate
- Succession (secondary) – climax community
How does the acidity of soils influence the ecosystem?
- Acidity of soil slows the rate of decomposition (discourages bacteria, decomposers and detritivores) – holly and yew develop in shrub layer. Beneficial for some species as nutrient uptake is greater
Describe how a microclimate affects the forest ecosystem.
- Microclimate – low canopy height has reduced evapotranspiration which has increased the wetness of the forest floor
Human influeces on an ecosystem;
What factors have changed in Epping forest over time?
- Conservation: Special Area of Conservation (beech woods developed in acidic soils with holly and yew in the shrub layer)
- Decline of hazel trees as a result of Anglo-Saxon woodland management
- Plagioclimax – oak, beech, ash (as it is a royal hunting ground, e.g. Epping Forest)
- Clearance (slash and burn) for residential areas (e.g. Hainault Forest for development - 100,000 trees cleared in 6 weeks), agriculture (arable and pastoral livestock grazing – e.g. Longhorn cattle in 2002) and recreational uses
- Introduction of non-native species (Chinese rhododendron)
Human influeces on an ecosystem;
What conservation has occured in Epping forest over time?
- Conservation: Management by the National Trust and Forestry Commission – designated as a Special Area of Conservation (SAC). The Wildlife and Countryside Act of 1981 has protected 66% with SSSI and SAC designation. Byelaws introduced which prohibit cycling and horse-riding in sensitive areas (Loughton Brook). Licenses required from the forest authorities for horse-riding.
- Pollarding for livestock grazing (modern pollarding of hornbeam trees to open the canopy), coppicing for fencing and fuel (modern coppicing of secondary woodland along the edges to stimulate shrub growth for nesting birds – e.g. nightingale)
Human influeces on an ecosystem;
What pollution has occured in Epping forest over time?
- Pollution: Trampling – reduced sensitive species (heather and moss)
- ‘Leave alone’ policy of National Trust (e.g. in Nap Wood) to maintain the natural nutrient cycle (e.g. no clearing)
- Economic activity
- Alien species (threaten endemic species with no predators/ outcompete through better adaptations to niches)
What is the Solent?
Salt Marsh (The Solent) – coastal vegetated mudflat (in a sheltered estuary/ margin of a spit or bar)
Stores and flows, what two food chains occur in The Solent?
- DETRITAL FOOD CHAIN: Dead rotted plants (decomposed) à detrital bacteria (chemotrophic and phototrophic) à crustacean à redshank
- GRAZING FOOD CHAIN: salt marsh grass/ algae/ eel grass à Brent goose
Stores and flows; describe the nutrient cycle in the salt marsh.
- Nutrient cycle contributed to by food chains precipitation, sunlight and decaying vegetation
